Answer : The coefficient of hydrogen gas in the balanced equation is, 4
Explanation :
Balanced chemical reaction : It is defined as the reaction in which the number of atoms of individual elements present on reactant side must be equal to the product side.
Single replacement reaction : It is defined as a reaction in which the the more reactive element replace the less reactive element.
The balanced chemical reaction will be:
[tex]Pb+4HNO_3\rightarrow Pb(NO_3)_4+4H^+[/tex]
In this reaction, lead is more reactive element than hydrogen so it can displace hydrogen element form its compound and form lead(IV) nitrate.
Thus, the coefficient of hydrogen gas in the balanced equation is, 4
